The invention relates to a superimposition steering unit, in which a superimposition angle set by the driver can, upon need, be superimposed by an additional angle.
The current motor vehicles, especially passenger vehicles, are, as a general rule, equipped with hydraulic or electro-hydraulic power-assisted steering units in which a steering wheel is mechanically connected with the steerable vehicle wheels in a force-locked manner. The servo-support unit is constructed in such a manner that actuators, such as hydraulic cylinders, for example, are positioned in the central area of the steering mechanism. The activation of the steering mechanism is supported, in reaction to the turning of the steering wheel, by a force produced by the actuators. The expenditure of energy by the driver during the steering process is thereby reduced.
Superimposition steering systems are already known. They are characterized in that the steering angle set by the driver can, upon need, be superimposed by an additional angle by means of an actuator. The additional angle is controlled by an electronic control unit and serves to increase the stability and agility of the vehicle, for example. Hydraulic or electrical actuators are used.